Khao Yai
has three main seasons, with an annual mean temperature of
23°C, though this varies greatly with the seasons.

Rainy Season: May-October. During this season, it
rains most days, resulting in stunning waterfalls. The
atmosphere is humid, with average daytime temperatures of
27°C, In the humidity, flora and fauna flourish, whilst
after the rain there is clean air and clear visibility
(great for photograph!).

Cold season: November- February. This is the most
popular time to visit Khao Yai, as clear, sunny and cool
weather are ideal for hiking and nice sunsets are common.
The days average around 22°C, while the nights can drop
to 10°C.

Hot Season: March-April Even in the hot season, Khao
Yai does not experience of heat felt elsewhere in the
country. Daytime temperatures reach between a high 20°C, to
a low 30°C, During this season it is dry and often
windy. Waterfalls can be dry by April.

Khao Yai
National Park consists of complicated mountains such as
Khao Rom, the highest about 1,351 meters, Khao Lam about
1,326 meters, Khao Keaw about 1,292 meters, Khao Sam Yod
about 1,142 meters, Khao Far Pha about 1,078 meters, Khao
Kampang about 875 meters, Khao Samor Poon about 805 meters
and Khao Kaew about 802 meters above sea level. Moreover,
the area has vastly grassy field alternating with productive
forest. The north and the east part are smoothly sloping
down, while the south and the west part are rising up. The
area is the source of five main rivers as follows.

1) Prachin Buri River

2) Nakhon Nayok River situated in the south part and
important for local agriculture and economy, meet each other
in Chachoengsao District to become Bangpakong River go to
the Gulf of Thailand.

3) Lam Ta Kong River

4) Praplerng River, in the north part, go to maintain the
agriculture of Korat Plateau and meet Moon River, the main
river of Southern Isan that goes to Khong River.

5) Muag Lek Stream, located in the northwest part and going
to Pasak River in Muag Lek District, is valuable for local
agriculture and cattle, and has water all the year round.